President Obama said today that the police shooting death of unarmed Missouri teen Michael Brown was "heartbreaking," and he urged those who are upset over the incident to remain calm.

Brown, an 18-year-old African American man, was shot multiple times and killed Saturday by a Ferguson, Mo., police officer. The days since the shooting have been marked by tense standoffs between Brown's supporters and heavily-armed police officers, along with riots and looting of stores on Sunday night.

"The death of Michael Brown is heartbreaking, and Michelle and I send our deepest condolences to his family and his community at this very difficult time," Obama said.

"I know the events of the past few days have prompted strong passions, but as details unfold, I urge everyone in Ferguson, Missouri, and across the country, to remember this young man through reflection and understanding," the President said in a statement. "We should comfort each other and talk with one another in a way that heals, not in a way that wounds. Along with our prayers, that’s what Michael and his family, and our broader American community, deserve."

Obama emphasized that Attorney General Eric Holder and the Department of Justice will be investigating the shooting as well as local police in St. Louis County, Missouri.

Earlier today, Ferguson police said they would not identify the officer who shot Brown due to safety concerns. Ferguson Police Chief Tom Jackson said there had been death threats made against the officer involved in the shooting, in which Brown, 18, was shot multiple times on Saturday afternoon.

Jackson's decision comes despite a call on Monday from Brown's father Michael Brown Sr. to identify the officer who shot his son several times, killing him.

"If the name of the victim is released, how is the name of the perpetrator not released? We cannot in good conscience ask for toxicology tests of Mr. Brown without asking for it of the officer," said Jamal Bryant, a pastor who appeared at a press conference with the Browns, their attorney Benjamin Crump, and the Reverend Al Sharpton today.

"This doesn't give the community confidence, it doesn't illustrate transparence or convince the community that the police aren't going to sweep this under the rug," Crump said.

The decision to not identify the officer came after another officer's name was released on social media as being the shooter, according to Jackson. "We've been getting death threats as a result to that officer. Officer safety is why we are not releasing the name (of the officer who shot Brown.) It's too volatile and dangerous. We think that the value of releasing his name is far outweighed by the safety at this point."

The Browns and civil rights leaders also used the press conference to urge supporters to remain calm and nonviolent in protesting the shooting. The pleas came after two nights in which protesters clashed with police and looted stores.

"I just want justice for my son. I really do. I need justice for my son," Michael Brown, Sr., said today. "I understand everybody has their own pains because they have losses too, but I need everyone to come together and do this the right way so we can get something done about this. No violence, man."

Sharpton emphasized the family's plea for non-violent protests.

"To become violent in Michael Brown’s name is to betray the gentle giant he was," Sharpton said. "I know you're angry. I know this is outrageous. When I saw that photo, the outrage rose up in me. But we cannot be more outraged than his mom and dad, and if they can hold their heads with dignity, then we can too."

Jeff Roberson/AP Photo

A makeshift memorial sits in the middle of the street where 18-year-old Michael Brown was shot and killed by police, Aug. 11, 2014, in Ferguson, Mo.

The town of Ferguson, a St. Louis suburb, was filled with tear gas as police in riot gear fired rubber bullets Monday night to disperse protesters, renewing tensions after Brown's shooting death on Saturday.

"We believe in the rule of the law but it's got to work both ways," Crump said at a press conference this afternoon.

Sharpton, Crump and others said they would only trust a full federal investigation into the shooting. The FBI is reviewing the case, looking into possible civil rights violations, while the St. Louis County police department is the lead investigating agency.

"What I can tell you is it started out as a routine encounter with two young men walking on the street. They were asked to get on the sidewalk," Jackson said. "It quickly became a violent encounter and then became a fight, some kind of fight inside the car. Shots were fired. I don't know how many."

Jackson said that the officer has been placed on administrative leave and his gun will be kept by investigators as evidence, though he is not prevented from having another weapon.

The officer will have to undergo two psychological evaluations as part of his administrative leave.

"He feels terrible about whole thing. He did not come to work with intention of this happening. He came to work to serve the community. He's sad and he is hurt. He's doing okay. It's a difficult thing," the chief said.

Jeff Roberson/AP Photo

People raise their hands in the middle of the street as police wearing riot gear move toward their position trying to get them to disperse, Aug. 11, 2014, in Ferguson, Mo.

Brown and a friend were walking to his grandmother’s house, when the friend says an unidentified officer asked them to get off the street. Police say one of the men fought the officer.

Brown’s mother, Lesley McSpadden, says her son didn’t fight anyone.

“Just because he’s 6-foot (tall), black walking down the city street doesn’t mean he fit the profile,” McSpadden said.